Model Output Discussion - The Start Of Winter

[snowangel32]

Look on the map then run this sequence & see how it crosses the pole

 

http://www.meteociel.fr/modeles/archives/archives.php?day=25&month=12&hour=0&year=1984&map=4&mode=2

 

S

Yh i see what you mean now thank you both for the info i think jan could be very intresting indeed if this comes off shame it couldn't be a week earlier for xmas.

[fergieweather]

Both models of the GFS 18z trying for the -EPO ridge @ 264-   -AO setting up around the 24-25th!

 

http://modeles.meteociel.fr/modeles/gfsp/runs/2014121118/gfsnh-0-324.png?18

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014121118/gfsnh-0-336.png?18

 

for reference ive annotated these important high pressures on this image

 

IGNORE THE COLOURS its just the locations

 

blank.png

 

S

EC 12Z clusters move more off +ve NAO into atlantic ridge and/or blocked scenarios post-22 Dec with northerly regime possible by 26th. Clearly too far off for any confidence and more continuity required, but recent tentative suspicion GloSea might be ahead of game by late Dec signal could yet become reality. However, long way to go and caution urged.

[SMU]

EC 12Z clusters move more off +ve NAO into atlantic ridge and/or blocked scenarios post-22 Dec with northerly regime possible by 26th. Clearly too far off for any confidence and more continuity required, but recent tentative suspicion GloSea might be ahead of game by late Dec signal could yet become reality. However, long way to go and caution urged.

 

Cheers, nice to see the GloSea, ECM clusters & GFS ens Mean seeing a pattern change-

 

Ian looking at the NH plots is the GloSea seeing the big -EPO pattern covering Western Alaska working in tandom with some sort of atlantic ridge ( 2 wave pattern )

 

Steve

[The Enforcer]

Model output though not showing much down south as clearer conditions through tomorrow with temperatures around 5-7c in South. Dropping after sunset though. With some winters showers to the NW showing on short range models. Once temperature and cold uppers reach Central & Southern areas the precipitation is not there it seems.

Here is the 6pm & Midnight 00Z Sat. From the Euro4

image.jpg. image.jpg

Thanks. That does seem rather odd as pressure isn't much higher then than this evening and there is bucketloads of precipitation around at the moment.

Edited December 11, 2014 by The Enforcer

[Mucka]

Hopefully we will be seeing plenty of this in the coming days in FI.

 

[SMU]

Hopefully we will be seeing plenty of this in the coming days in FI.

 

 

Yes

 

Classic -EPO > atlantic ridge response....

S

Edited December 11, 2014 by Steve Murr

[Mucka]

Yes

 

Classic -EPO > atlantic ridge response....

S

 

And we all love a classic. 

 

Be great to see something like that start appearing in the Ops and to follow it through into hi res.

Nice spot and along with Ian's latest update there are plenty of reasons for optimism again for coldies.

Really looking forward to future output again now we may have something to chase. 

[IDO]

  RyanMaue

00z GFS parallel was scrapped. Cascading job failure at NCEP. Oh well.

12/12/2014 05:41

 

The GFS runs keep flip flopping with regard to the TM and PM flow. The 0z is a mild run overall so not to sure we should take it serious and without the Parallel the mean is probably the best guide:

 

 

The GEFS show no extended cold just the sine wave signature of a westerly flow alternating between PM and TM shots. Therefore the mean sits around average for most of D7-16.

 

D10 charts from the GFS C and GEM & ECM at D9:

 

   

 

The same long wave pattern just issues with timing. Looking at the GEFS at D16 for some sort of instruction and again there is no strong cluster. About 33% are like the Control, with a more organised PV:

 

About 33% are more meridional like this: 

 

The rest are flat but with the PV still disorganised. So the next 10 days or so still remains zonal averaging out as normal December fare. After that it is most likely a continuation of the upcoming pattern. No blocking signal showing up. As for the strat developments (SSW), no doubt we will get an update from the experts later, but it would not surprise me again if it is delayed further; maybe after mid-Jan now?

 

 

CFS still seeing a blocked Jan but with the core cold well to our east: 

 

 

[bluearmy]

Whilst the mean ECM 32 dayer is tough to analyse, I would suggest week 3 holds quite a lot of members that would find favour on here.

[terrier]

We stick with the westerly pattern on the output this morning with us flipping between tm and pm shots. Pretty underwhelming to be honest. Think until we see the nao going negative we're going to struggle to get the eye candy charts into the reliable timeframe.

[Ali1977]

If there are signs of change in around 2 weeks then you would hope some nice FI charts will start appearing in the next few days. It's been a while since we've had charts screaming potential in FI never mind in the short range, any would go down well on here. Cold air looks to be digging into the East coast of the USA around Xmas, hopefully that will help form a ridge into Greenland rather than generate the PV and über powerful jet stream like last year.

[damianslaw]

Looking beyond reliable timeframe -indeed well beyond, which is something I wouldn't do, but there are signs of a pattern change and it may well come courtesy of the azores high - GFS is suggesting it will build eastwards but more crucially northwards as well enveloping the UK over Christmas - and thereafter continue to build northwards killing off the advances of the atlantic whilst at the same time linking with developing heights further to our north - such movement would certainly enable a much colder outlook as we move to New Year.

 

Its all along way off, but those who are bemoaning the advances of the azores high in terms of killing off likely chance of cold conditions this side of the New Year, may be none too wise, it could easily end up being the eventual trigger to the colder pattern they are looking for.

 

Back to the reliable, middle of next week will see a very similar set up to Wed-Fri pattern of this week, another deep low, not quite as deep and slightly further north will pull down northwesterlies by Friday with further wintry showers in the NW.

[Polar Maritime]

Its all along way off, but those who are bemoaning the advances of the azores high in terms of killing off likely chance of cold conditions this side of the New Year, may be none too wise, it could easily end up being the eventual trigger to the colder pattern they are looking for.

 

Wise words there Damian, As you say something has to move to give. GFSP continues to show Height's pushing up into the Poles around Christmas this morning.

 

Edited December 12, 2014 by Polar Maritime

[TEITS]

Looking at the overall output and there is very little to suggest a change. Sadly there is nothing to suggest a change towards a significant nationwide cold spell even in distant F.I.

 

The ensembles do give the slightest hint pressure may rise across the UK via the Azores high but equally it could remain to the S. You can see this scatter below with the GFS Op having a much higher SLP than the mean.

 

http://max.nwstatic.co.uk/ensimages/ens.20141212/00/prmslCambridgeshire.png

[Frosty.]

Lots more cold zonality in the pipeline but with slightly milder air during the wet and windy spells and further on we may catch a break from the disturbed pattern with a quieter phase with overnight frost and fog. I'm really disgusted to see personal abuse on here despite all the warnings, hopefully a decent size ban for the individual involved. :-)

[bluearmy]

Wise words there Damian, As you say something has to move to give. GFSP continues to show Height's pushing up into the Poles around Christmas this morning.

 

Except its yesterday's 18z - the 00z para didn't run!

[Severe Siberian icy blast]

Wise words there Damian, As you say something has to move to give. GFSP continues to show Height's pushing up into the Poles around Christmas this morning.

 

Ummmm no it doesn't not really . That's surface highs over Greenland . Still nothing in the models this morning to suggest anything in any way . We all look desperately with cold blinkers clouding our judgement . But in reality untill we see evidence on the models there's no chance of change

[Polar Maritime]

Except its yesterday's 18z - the 00z para didn't run!

 

Wup's, Cheers for that Blue.. Any news as to why?

[Penrith Snow]

Some dreadful charts on GFS and ECM leading up to Christmas which if verified would be very mild indeed, who invited Uncle Barty to the Christmas party!

I think also that the AH ridging into Europe route to cold is extremely dangerous and we are more likely to be left with a New Year long fetch south westerly than easterly.

Much safer would be next weekends northwesterly to become a northerly followed by a mid Atlantic ridge, not likely I admit but the AH ringing strongly east will be a disaster IMO.

Still all FI so time for it to change but the signs are not good as we approach the festive season.

Andy

[Polar Maritime]

Ummmm no it doesn't not really . That's surface highs over Greenland . Still nothing in the models this morning to suggest anything in any way . We all look desperately with cold blinkers clouding our judgement . But in reality untill we see evidence on the models there's no chance of change

 

As i said (Although It's yesterdays 18z as Blue points out) It does show Heights push into the 'Poles'. No mention of Greenland..

Edited December 12, 2014 by Polar Maritime

[IanM]

Wup's, Cheers for that Blue.. Any news as to why?

 

The parallel was scrapped due to a cascading error apparently.

[Polar Maritime]

Cheers Ian.

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY FRIDAY DECEMBER 12TH 2014.

NEXT UPDATE SATURDAY DECEMBER 13TH 20:00

THE CURRENT GENERAL SITUATION Fronts will clear SE across the UK today followed by a ridge of High pressure tonight and tomorrow.

MODELS-2 WEEK HEADLINE Remaining changeable with rain at times especially across the North and West. Temperatures generally close to or a little above average but a few colder periods over the North when showers could turn wintry.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble forecast continues to show signs of maintaining a West to East flow in the vicinity of the UK over the next few weeks. However, the speed of the flow is looking like weakening with time while maintaining it's positioning.

GFS OPERATIONAL The GFS operational this morning shows another week or so of mobile Atlantic Westerlies across the UK with rain or showers at times with snow on Northern hills at times. Then a change towards higher pressure moves up across the UK from the SW in week 2 with frost and fog and anticyclonic type weather developing for a time. Towards the end of the run the high recedes SE and mahes for slack Southerly winds across the UK with a lot of dry, rather cloudy and benign conditions with less in the way of frost and fog by night and the return of some rain at times across the North and West.

THE GFS PARALLEL RUN The GFS Parallel run is not available at time of issue.

THE GFS CONTROL The GFS control run today maintains a basically mobile Westerly flow across the UK over the period. There will be spells of milder and rainier conditions alternating with short colder periods with showers especially across the North. In the quieter periods frost at night may occur but the end of the run ends with the UK weather governed by a large High pressure zone down to the SW.

THE GEFS ENSEMBLES The GEFS Ensembles are indicative that Low pressure to the North of the UK and High to the South and SW will continue to be dominant through much of the period but the trend towards a weaker Jet profile and weaker pressure gradients over the UK opens the door for other solutions to be shown within this long lasting pattern.

UKMO UKMO today shows a strong Westerly flow across the UK towards the middle of next week with deep Low pressure to the North. With temperatures close to average it will feel chilly in the wind and all areas will see further spells of rain and showers at times with a little snow on the higher Northern hills.

THE FAX CHARTS The Fax Charts show a period of variable weather alternating between sunshine and showers and cloudier periods with more prolonged rainfall and blustery winds as each succession of troughs pass over in generally close to average temperatures.

GEM GEM shows little change in conditions to that we have experienced over recent days with spells of rain alternating with colder NW winds with showers, wintry in the North. Later in the run High pressure to the SW inches in towards Iberia and Biscay bringing more westerly winds with rain at times and less colder interventions away from the far North.

NAVGEM NAVGEM too shows a flattening of the pattern across the UK as the alternating spells of rain with colder showery conditions is replaced by milder Westerly winds with rain at times more towards the North and West looking likely one week from now.

ECM ECM this morning shows a mobile Westerly type pattern maintained through it's duration this morning with all of the UK weather through the period generated over the Atlantic. As of late there will be spells of rain alternating with colder and windy periods with showers, wintry in the North. High pressure does show signs of becoming somewhat more influential in the South later by a reduction in the amounts of rainfall and in the North by bringing strong but milder Westerly winds for longer periods than currently.

ECM ENSEMBLES This morning's still reflect a distorted picture of Low pressure to the North and High pressure ever closer to the South of the UK. However, a variety of options are shown in indicidual members that show something more akin to a Northerly component to the weather as a trough resides to the East with higher pressure over the Atlantic but as it stands it's far from being a given evolution.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There still appears to be little shift away from a Westerly profile of weather across the UK with further spells of rain and wintry showers in the North before a slow shift towards a flattern and somewhat milder period is shown in the second half of the period..

MY THOUGHTS The models seem slow to respond to any upwind signals of a change of pattern towards the end of the year and while we wait for that to filter through we continue to look at charts which resemble the pattern we have seen now for several weeks. High pressure remains stubbornly locked down to the SW of the UK, near the Azores and with deep Low pressure areas continuing to move East to the North of the UK carrying spells of wind and rain followed by showers. Over recent runs the trend towards milder air taking the upper hand next week has receded somewhat and it now looks like further colder air will filter down across northern Britain at times maintaining the occasionally wintry flavour of weather up there. Wintriness is unlikely across the South with average temperatures likely as a result. Then as we move towards Christmas it looks distinctly a green one for many as High pressure is shown to track ever closer to SW Europe bringing a flatter westerly flow across the UK with rain at times gradually becoming most prolific towards the North and West while temperatures recover to average or a fraction above. There are signs though that the Jet stream and Low pressure profile around the Iceland and Greenland area will become less pronounced given tome and this maybe the first signs of a pattern shift after Christmas. We must be mindful though we are talking grains of sand in a desert and there is a wealth of weather to get through as well as all the usual if's and but's before something more akin to what folks want to see become more likely but for the moment we must continue to endure a substantial period of mobile Atlantic Westerly driven weather with all the natural variability that can provide.

[nick sussex]

I think its a case of scratching around for a bit of excitement with the models as they are.

 

Upstream a fast zonal pattern is expected so any ridging even if it does occur will be flattened quickly, in terms of next weeks possible wintry blip some uncertainty upstream with how this low will develop near the ne USA so this does impact on that high pressure cell that works out of Canada.

 

Looking towards days 9 and 10 on the ECM ensemble spreads still some solutions that take lower heights se in towards the northern Med so this would translate into the Azores high being held further west.

 

Thats about the sum of it today, off to watch some paint drying now!

[ItNeverSnowsInWindsor]

Some dreadful charts on GFS and ECM leading up to Christmas which if verified would be very mild indeed, who invited Uncle Barty to the Christmas party!

I think also that the AH ridging into Europe route to cold is extremely dangerous and we are more likely to be left with a New Year long fetch south westerly than easterly.

Much safer would be next weekends northwesterly to become a northerly followed by a mid Atlantic ridge, not likely I admit but the AH ringing strongly east will be a disaster IMO.

Still all FI so time for it to change but the signs are not good as we approach the festive season.

Andy

The GFS 0Z is a warm outlier from 22 Dec so I wouldn't take much notice of it after that period, Slight chance it might be setting the trend but seriously doubt it with recent developments meant to take hold in the final week of December as continually mentioned by the Met Office.

 

Edited December 12, 2014 by prolongedSnowLover